1. Field of the Invention
The present invention relates to a process of fuel combustion. More particularly, the present invention relates to a process for burning fuel with reduced soot and/or NO.sub.x discharge.
2. Description of the Related Art
Soot is generated when there is not enough oxygen around the fuel molecules or fuel particles on burning. Such soot is discharged into the air causing air pollution. Therefore, great efforts have been made in order to inhibit the generation of soot. For example, in the art of internal combustion engines which burn fuel in a combustion chamber, initial combustion is done in a condition such that the fuel-air ratio is rich and later combustion is done in a condition such that fuel-air ratio is lean in order to limit the generation of soot during later combustion as disclosed in Japanese Unexamined Patent Publication No. 3-3920.
However, if the fuel-air mixture is burned in a condition such that fuel-air mixture is rich, soot is always generated, thus soot is generated during initial combustion in the above internal combustion engine. It is difficult to inhibit the generation of soot on burning fuel in internal combustion engines and in other fields. This is due to the fact that the mechanism of soot generation is not resolved. If the mechanism of soot generation is resolved, the generation of soot can be inhibited.